Stress-constrained Structural Topology Optimization with Design-dependent Loads

• Main Author: Lee, Edmund
• Other Authors: Martins, Joaquim R. R. A.
• Language: en_ca
• Published: 2012
• Subjects: topology optimization; design dependent loads; pressure loads; self-weight; stress constraints; block aggregated constraints; 0538
• Online Access: http://hdl.handle.net/1807/32254

Topology optimization is commonly used to distribute a given amount of material to obtain the stiffest structure, with predefined fixed loads. The present work investigates the result of applying stress constraints to topology optimization, for problems with design-depending loading, such as self-weight and pressure. In order to apply pressure loading, a material boundary identification scheme is proposed, iteratively connecting points of equal density. In previous research, design-dependent loading problems have been limited to compliance minimization. The present study employs a more practical approach by minimizing mass subject to failure constraints, and uses a stress relaxation technique to avoid stress constraint singularities. The results show that these design dependent loading problems may converge to a local minimum when stress constraints are enforced. Comparisons between compliance minimization solutions and stress-constrained solutions are also given. The resulting topologies of these two solutions are usually vastly different, demonstrating the need for stress-constrained topology optimization.